Method and apparatus for making composite oil containers of spirally wound strips



c. K. DUNL'AP, JR. ETAL- 3,159,515

Dec. 1, 1964 METHOD AND APPARATUS FOR MAKING COMPOSITE OIL. CONTAINERSOF SPIRALLY WOUND STRIPS Flled March 19, 1962 3 Sheets-Sheet 1INVENTORSI gHARLEfi K. bum.

AP, J12. Avu C. ALEXANDER, BY PHI LAP G. HART and.

/ Q Wok/fir JAMEs P. HAL

Dec. 1, 1964 c. K. DUNLAP, JR.. ETAL 3,159,515

' METHOD AND APPARATUS FOR MAKING COMPOSITE OIL S OF SPIRALLY WOUND STRI3 Sheets-Shee CONTAINER Filed March 19, 1962 INVENTORSI CHARLESK.DUNLAP,J2.,

.5 bAvn C. ALEXANDER, BY PH\L.\\ G. HART and JAMEE: P. HAx L 7 WATTORNEY c. K. DUNLAP, JR. ET AL 3,159,515 D AND APPARATUS FOR MAKINGCOMPOSITE OIL Dec. 1, 1964 METHG Filed March 19, 1962 CONTAINERS OFSPIRALLY WOUND STRIPS 3 Sheets-Sheet 3 m i Y M H iv m M y 52 M T /5/KL.. A w w m i P N V\ C P I I United States Patent METHOD AND APPARATUSFOR MAKING COMPOSITE OIL CONTAKNERS 0F SPI- RALLY WOUND STRlPS CharlesK. Dunlap, Jr., David C. Alexander, and Philip G. Hart, Hartsville, andJames P. Hall, Darlington, S.C., assignors to Sonoco Products Company,Hartsville, S.C., a corporation of South Carolina Filed Mar. 19, 1962,Ser. No. 180,666 3 Claims. (Cl. 156-190) This invention relates tocontainers and more particularly to tubular containers for liquidmaterials such 'as oil and the like.

In the packaging of liquid and semiliquid materials, containers or cansof metal are generally employed due to the obvious advantages of metalover many other materials for such containers. For instance, engine oilpackaged for sale to the typical motorist is packaged in a tubular metalcontainer in relatively small quantities, the onequart capacity oil canbeing the most popular.

The use of metal for the construction of containers used for materialssuch as oil imparts numerous highly desirable features to suchcontainers including strength and ruggedness so as to resist denting,weathering, puncturing and other damaging effects to which such acontainer is subjected during handling, shipment and the like. Metalcontainers are also generally characterized by ready printability of themetal outer surface so as to provide an attractive and readilymarketable product. Most importantly, metal is impermeable to thepenetrating action of oil and other liquid materials and can be treatedto be relatively inert to chemical attack by the packaged material.

However, the high cost of metal and metal fabrication has inspiredconsiderable development work searching for less expensive substitutematerials for metal to be used in the construction of such containers.Many substitute materials for metal have been proposed including fibrousmaterials such as paper impregnated or laminated at least on the sideforming the inner surface of the container with a suitable material torender it impervious to oil and other penetrating packaged materials. Itis generally accepted that some sacrifice in strength cannot be avoidedwith theuse of materials other than metal for the oil container but theimpermeability feature of a metal can is required to be present incontainers made firom other materials.

It has been generally proposed that paper is the most suitablesubstitute material for metal for containers and many efforts have beenmade to perfect a wound paper tube either convolutely or spirally woundin which liquid materials such as oil can be packaged and which isimpermeable to the penetrating action of the oil. The relatively lowcost of paper and the highly developed techniques for winding papertubes from which the container bodies can be made have brought aboutconsiderable development work leading up to such a container. However,even though coated papers, laminated papers and the like provide a highdegree of impermeability for the inner surface of the wound papercontainer bodies, the seam onthe inner wall of the container body is asource of leaking or wicking generally and efforts to produce aninexpensive impermeable container acceptable for the packaging of liquidand semiliquid materials have not met with .the desired degree ofsuccess.

It has been found that while the use of a plastic coating or a metalfoil laminate on the inner surface of such containers providesconsiderable leakproofing, the slightest pinhole or exposed fiber oninner surface produces a wicking and attendant leaking of oil throughthe container wall. This wicking and leaking is particularly prevalentalong the seam of the container even with overlapping plies and the likeas a result of the difiiculty of producing a seam completely closed byoil impermeable material.

The use of metal for containers has other disadvantages in addition tohigh cost as disposal of empty metal oil containers has always posedsomewhat of a problem due to the non-combustibility of the metal and thedifiiculity of collapsing the metal container. Furthermore, the weightof the metal container is always a cost factor to consider when freightcosts (are involved.

Accordingly, a primary object of this invention is to provide a new andnovel method for making a leakproof container body using fibrousmaterial such as paper.

Another object of this invention is to provide a new and novel method offorming a leakproof container body for an oil container utilizingfibrous material such as paper which is completely impermeable topenetrating liquids such as oil and which is inexpensive and rugged inconstruction.

A further object of this invention is to provide a new and novel methodof spirally winding strip material including paper and metal foil into atubular body for an oil container in which the spiral seam is completelysealed so as to prevent wicking or leaking of the liquid such as oilpackaged in the container.

A still further object of invention is to provide a new and novelapparatus for making a leakproof body for the packaging of materialssuch as oil and the like.

Still another object of this invention is to provide a new and novelapparatus for spirally winding paper and metal foil strip material intoa le-akproof composite oil container tubular body.

This invention further resides in the provision of a new and novelapparatus and method for spirally winding paper strips and foillaminated paper strips together to form a composite oil containertubular body in which the inner spiral seam is completely sealed againstoil wicking and leaking and which tubular body may be readily closed ateither end with metal ends or the like to provide a rugged, leakprootcontainer of inexpensive construction utilizing readily availablematerial and provided with a pleasing outward appearance.

Other objects and advantages of the invention will become apparent fromthe following description taken in connection with the accompanyingdrawings.

The objects stated above and other related objects in this invention areaccomplished by spirally winding a plurality of strips on anelongatedrnandrel with adhesive therebetween to form a spiral tube severable intotubular container bodies. The inner strip comprises oil imperviousmaterial such as foil laminated paper with the edges of adjacentconvolutions in abutting relationship to form a spiral seam. Arelatively narrow strip of oil impervious material such as foil coatedon its outwardly facing side with a thermoplastic adhesive is spirallywound between the inner strip-and the mandrel across the spiral but-tseam. A portion of the mandrel adjacent the spiral tube forming end isheated to activate the thermoplastic adhesive on the narrow strip andadhesively secure the narrow strip to the inner strip to completely sealthe seam. The spiral tube is then cooled to set the thermoplasticadhesive and form an oil impervious ply for the container body.

The novel features which are believed to be characteristic of theinvention are set forth with particularity in the appended claims. Theinvention itself, however, both as to its organization and method ofoperation may be best understood by reference to the followingdescription taken in conjunction with the accompanying drawings inwhich:

FIGURE 1 is an isometric view of a composite oil container incorporatingthe tubular body formed in accordance with the invention;

FIGURE 2 is a plan view of a spiral tube winding ap paratus illustratingthe carrying out of the novel method of the invention;

FIGURE 3 is an enlarged isometric view of a portion of the windingapparatus of FIGURE 2;

FIGURE 4 is an enlarged sectional view taken substantially along line4-4 of FIGURE 3 in the direction of the arrows;

FIGURE 5 is a sectional view taken substantially along line 5-5 ofFIGURE 3 in the direction of the arrows;

FIGURE 6 is a sectional view of a portion of the men drel incorporatedin the apparatus of FIGURE 2;

FIGURE 7 is a sectional view similar to FIGURE 6 of another portion ofthe mandrel;

FIGURE 8 is a sectional view similar to FIGURE 6 illustrating stillanother portion of the mandrel; and

FIGURE 9 is an enlarged sectional view taken substantially along line 99of FIGURE 1 in the direction of the arrows.

As referred to above, the novel method and apparatus of the invention isemployed in the production of tubular bodies for containers such as oilcans or the like and one such container for oil is shown in FIGURE 1 andis identified generally by the numeral 10. It should be understood thatthe invention is suitable for the production of bodies for containersused to package liquid materials, semiliquid materials or any other typeof materials which is prone to cause container leakage but referenceshereinafter will be made to a container used for the packaging of oil.

The container 10 comprises a spirally wound tubular body 11 having anexterior spirai seam I2 which body is formed from a plurality of stripsof suitable material such as paper and the like as will be describedhereinafter adhesively secured together in overlapping relationship.Prior to filling, the container 10 is first sealed at one end with asuitable circular disk or end 13 preferably formed from metal with anedge seam 14- and after filling with oil or the like is sealed at itsother end with an end 16 utilizing a similar edge seam 17 to form acompletely closed container.

Referring now to FIGURE 2, there is shown spiral tube winding apparatussimilar generally to conventional tube winding apparatus having certaincomponents constructed in accordance with the invention. As is wellknown, the spiral tube winding apparatus of FIGURE 2 includes a bed 18,a head 19 to which is secured at one end a mandrel 21 constructed inaccordance with the invention. A continuous belt 22 is provided whichadvances over pulleys 23 and which is looped around the mandrel in theconventional manner as shown to advance a spiral tube 24 being formed inaccordance with the invention and advanced in the direction of the arrowI. As will be explained hereinafter the tube 24- is severed into uniformlengths to form the container bodies 11.

In accordance with the novel construction of the invention, the mandrel21 is provided with a heated section A adjacent its tube forming end anda cooled section B as shown in FIGURES 6, 7 respectively. As can beseen, the left hand end of mandrel section B is arranged to bethreadedly connected to the right hand end of mandrel section A asviewed in FIGURES 6, 7. The mandrel 21 is also provided with a section C(FIGURE 8) forming an extension the left hand end of which is arrangedto be threadedly connected to the right hand end of mandrel section B asviewed in FIGURES 7, 8.

Referring now to FIGURES 1-8, the mandrel 21 contains a tubular innershell 31 and an outer shell designated generally by the numeral 32 thethree sections of which are identified as 32a, 32b and 320 in FIGURES6-8 respectively. The tubular inner shell 31 which extends throughoutmandrel sections A, B is supported in coaxial relationship with theouter shell 32 by means such as an end plate 33 as shown best in FIGURE3, a coupling collar 34 as shown in FIGURE 6 and an end collar 36 asshown in FIGURE 7 to form an annular hot cavity 37 in mandrel section Aand a cold cavity 38 in mandrel section B.

The coupling collar 34 is fixed to the outer shell section 32a and innershell 31 by means such as welding and the like and is externallythreaded at 41 for a threaded connection with an internally threaded end42 on mandrel section B of FIGURE 7. The other end of mandrel section Bis internally threaded at 43 for a threaded connection with anexternally threaded portion 44 on the mandrel section C of FIGURE 8. Theexternally threaded portion 44 is formed on an enlarged portion 46 of aninner tube 47 threadedly connected at one end to the outer shell section320 as shown and at its other end by means of an annular spacer 48 forsupporting the tube 47 within the mandrel outer shell section 32c.

When the mandrel portions A-C shown in FIGURES 6-8 respectively areassembled together as described above, the outer shell sections 32a, 32band 32c form a continuous outer mandrel surface along which the spiraltube 24 advances.

The mandrel 21 has associated therewith an elongated shaft 51 which issupported for reciprocating movement within the mandrel inner shell 31on bushings 52-54 and 56 positioned as shown in FIGURES 6-8. The shaft51 is arranged to be connected to a cut-off device for the spiral tube24 and as it forms no part of this invention, the cut-ofi? device isneither shown nor described.

The annular hot cavity 37 is sealed at its ends by means of the plate 33and collar 34 and is arranged to be supplied with steam from a suitablesteam source 57 (FIG- URE 2) by means of a conduit or hose 58 threadedlyconnected by means of a fitting 59 to a threaded opening 61 in the plate33 which opening is in communication with the hot cavity 37. Condensateis arranged to be removed from the lower portion of the hot cavity 37 bymeans of an outlet conduit or hose 62 connected by means of a fitting 63to a threaded opening 64 within the plate 33. Thus by injecting steaminto the cavity 37 of the mandrel section A, the mandrel shell section32a is heated.

Mandrel section B is arranged to be cooled by cold water from a coldwater source identified in FIGURE 2 by the numeral 66 which hasconnected thereto an inlet conduit 67 entering the mandrel 21 through anopening 63 in the mandrel end bushing 52. The conduit 67 communicateswith the annular cavity 38 in mandrel section B by extending through anopening 69 in the wall of the mandrel inner shell 31. In the upperportion of the cavity 38 in the mandrel section B, an outlet conduit 71is provided having an inner end extending through an opening 72 in thewall of the mandrel inner shell 31. The outlet conduit 71 similarlypasses through an opening 73 in the mandrel end bushing 52.

The tubular body 11 of the container 10 wound by means of the apparatusof FIGURE 2 is formed from a plurality of strips of material with aninner strip 81 of oil impervious material such as foil laminated paperunwound from a supply roll 82 suitably supported adjacent the apparatusof FIGURE 2. In order to insure that the foil-paper strip 81 iscompletely impervious to oil, the foil laminate is preferably coated onits exposed surface with an oil impermeable material such as a clearplastic material or the like. The strip 81 is fed onto the mandrel 21with the foil side adjacent the mandrel, sections A, B having beenheated and cooled by the steam and cold water from the sources 57, 66respectively.

Two additional strips 83, 34 of fibrous material such as paper are thenspirally wound in overlapping relationship with the inner strip 81 asshown. Strip 83 is unwound from a suitably supported supply roll 86 andis passed through an adhesive applicator 87 of conventional constructionwith the strip immersed in the adhesive bath for thorough coating. Thestrip 84 is unwound from a suitably supported supply roll 88 so that thestrips 81, 83, 84 are all adhesively secured together by means of theadhesive on opposite sides of the strip 83. It will be noted that thehot section A of mandrel 21 extends substantially up to the point atwhich a tube is formed with the strips 81, 83, 84 as shown in FIGURE 2.

As shown best in FIGURE 4, the adjacent edges of the convolution of theinner strip 81 are wound in abutting engagement to form a butt seam 91.In accordance with the novel method of the invention, a relativelynarrow strip 92 of oil impervious material preferably foil is unwoundfrom a supply roll 93 and is spirally wound together with the strip 81.The strip 92 has a thermoplastic adhesive coating 94 and is wound ontothe mandrel 21 between the inner strip 81 and the outer surface of themandrel with thermoplastic coating in contact with the foil side ofstrip 81. Thus the narrow foil strip 92 extends across the butt seam 91of strip 81. Any suitable thermoplastic adhesive may be used for thecoating 94 on the strip 92.

The heat of the mandrel outer shell section 32a, as the narrow coatedsealing strip 92 and foil laminated paper strip 81 are wound thereonsoftens and activates the thermoplastic adhesive coating 94 so that abond develops between the sealing strip 92 and the inner foilpaper strip81, and the butt seam 91 is completely sealed.

As the formed spiral tube is advanced in the direction of the arrow I bymeans of the belt 22, it passes over the cold section B of the mandrel21 chilling the thermoplastic adhesive 94 setting it in a permanentbond. The resulting tube leaving the mandrel cold section B is a spiraltube formed of the strips 81, 83, 84 and the narrow sealing strip 92 inseal-ing relationship across the inner ply butt seam 91.

In the preferred embodiment, an outer foil laminated paper strip 96 iswound in overlapping relationship with the ply formed by strip 84. Theouter surface of strip 96 is preferably printed with suitable indiciafor advertising and identification purposes or the like. The strip 96 ispreferably spirally Wound with the other strips down from the belt 22 toavoid damage to the foil layer. The foil-paper strip 96 is shown beingunwound from a supply roll 97 whereupon it is passed through a glueapplicator 98 having a glue applicator roll 99. The resulting tube 24 istherefore a multi-ply tubular structure forming the body 11 for an oilcontainer which after filling can be sealed with the metal ends 13, 16to form a leakproof container.

It can be seen with the novel arrangement of this invention that atubular body for a container may be constructed in a simple and easymanner using fibrous material such as paper as a substitute for metalwhich container is suitable for the packaging of highly pentrativeliquid and semi-liquid materials such as oil or the like. The method ofthe invention permits the use of conventional spiral tube windingtechniques and apparatus characterized by ease of operation and low costand at the same time permits a continuous tube to be formed which can besevered into suitable lengths for container bodies having an innersurface which is completed impermeable to oil and the like. The novelmethod of sealing the internal spiral seam is accomplished inexpensivelyutilizing conventional spinal winding techniques so that the internalspiral seam is completely closed to the packaged material. The apparatusof the invention incorporates a novel spiral tube winding mandrel whichwhile serving as does the mandrel presently used in conventionalmachines additionally performs a heating and cooling function on thenovel wound tube of the invention so as to permanently bond togetherstrips employed in winding the novel tubular body of the invention.

While there has been described what at present is considered to be thepreferred embodiment of the invention, it will be understood by thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention and, therefore, it is theaim of the appended claims to cover all such changes and modificationsas fall within the true spirit and scope of the invention.

Having thus described the invention, what is claimed is:

1. A method of making a composite oil container body comprising thesteps of, spirally winding a plurality of strips adhesively securedtogether on an elongated mandrel to form a container body, said stripsincluding an inner strip of leakproof material wound with the edges ofadjacent convolutions in abutting relationship to form a spiral seam,simultaneously spirally winding a relatively narrow strip of leakproofmaterial, coated on its outwardly facing side with a thermoplasticadhesive, across said seam and adjacent to said mandrel, heating aportion of said mandrel beneath said wound narrow strip and said innerstrip to activate the thermoplastic adhesive on said narrow strip andadhesively secure said narrow strip to said inner strip and cooling saidheated narrow strip to set said thermoplastic adhesive and form aleakproof inner ply for said container body.

2. A method of making a composite oil container body comprising thesteps of, spirally winding a plurality of strips adhesively securedtogether on an elongated mandrel to form a container body, including aplurality of paper strips and an inner strip of foil laminated paperwound with the foil of said foil laminated paper adjacent said mandreland with the edges of adjacent convolutions in abutting relationship toform a spiral seam, simultaneously spirally winding a relatively narrowstrip of foil, coated on its outwardly facing side with a thermoplasticadhesive, across said seam and adjacent to said mandrel, heating aportion of said mandrel beneath said wound inner strip of foil laminatedpaper and said wound narrow foil strip to activate said thermoplasticadhesive and adhesively secure said narrow strip to said inner strip andcooling a portion of said mandrel adjacent said heated portion to setsaid thermoplastic adhesive and form a leakproof inner ply for saidcontainer body.

3. In a spiral tube winding apparatus, the combination of an elongatedmandrel for winding a plurality of spirally wound overlapping stripsadhesively secured together into a spiral tube, said strips including aninner strip wound with the edges of adjacent convolutions in abuttingrelationship to form a spiral seam and a narrow strip, having anoutwardly facing thermoplastic adhesive coating wound across said spiralseam and adjacent said mandrel, means in said mandrel for heating alongitudinally extending portion of said mandrel to heat saidthermoplastic adhesive coating and adhesively bond said narrow strip tosaid inner strip, and means in said mandrel for cooling a longitudinallyextending portion of said mandrel adjacent said heated portion to cooland set said thermoplastic adhesive to thereby maintain said strips in abonded relationship.

References Cited by the Examiner UNITED STATES PATENTS 1,944,970 l/ 34Ditfenbach 93-80 XR 2,131,343 9/ 38 Cordiano 93-94 XR 2,411,542 11/46Ilch.

2,555,380 6/51 Stuart et a1 229-45 XR 2,766,160 10/56 Bentov 156-461 XRFOREIGN PATENTS 683,206 11/52 Great Britain. 825,304 12/59 GreatBritain.

EARL M. BERGERT, Primary Examiner.

1. A METHOD OF MAKING A COMPOSITE OIL CONTAINER BODY COMPRISING THESTEPS OF, SPIRALLY WINDING A PLURALITY OF STRIPS ADHESIVELY SECUREDTOGETHER ON AN ELONGATED MANDREL TO FORM A CONTAINER BODY, SAID STRIPSINCLUDING AN INNER STRIP OF LEAKPROOF MATERIAL WOUND WITH THE EDGES OFADJACENT CONVOLUTIONS IN ABUTTING RELATIONSHIP TO FORM A SPIRAL SEAM,SIMULTANEOUSLY SPIRALLY WINDING A RELATIVELY NARROW STRIP OF LEAKPROOFMATERIAL, COATED ON ITS OUTWARDLY FACING SIDE WITH A THERMOPLASTICADHESIVE, ACROSS SAID SEAM AND ADJACENT TO SAID MANDREL, HEATING APORTION OF SAID MANDREL BENEATH SAID WOUND NARROW STRIP AND SAID INNERSTRIP TO ACTIVATE THE THERMOPLASTIC ADHESIVE ON SAID NARROW STRIP ANDADHESIVELY SECURE SAID NARROW STRIP TO SAID INNER STRIP AND COOLING SAIDHEATED NARROW STRIP TO SET SAID THERMOPLASTIC ADHESIVE AND FORM ALEAKPROOF INNER PLY FOR SAID CONTAINER BODY.
 3. IN A SPIRAL TUBE WINDINGAPPARATUS, THE COMBINATION OF AN ELONGATED MANDREL FOR WINDING APLURALITY OF SPIRALLY WOUND OVERLAPPING STRIPS ADHESIVELY SECUREDTOGETHER INTO A SPIRAL TUBE, SAID STRIPS INCLUDING AN INNER STRIP WOUNDWITH THE EDGES OF ADJACENT CONVOLUTIONS IN ABUTTING RELATIONSHIP TO FORMA SPIRAL SEAM AND A NARROW STRIP, HAVING AN OUTWARDLY FACINGTHERMOPLASTIC ADHESIVE COATING WOUND ACROSS SAID SPIRAL SEAM ANDADJACENT SAID MANDREL, MEANS IN SAID MANDREL FOR HEATING ALONGITUDINALLY EXTENDING PORTION OF SAID MANDREL TO HEAT SAIDTHERMOPLASTIC ADHESIVE COATING AND ADHESIVELY BOND SAID NARROW STRIP TOSAID INNER STRIP, AND MEANS IN SAID MANDREL FOR COOLING A LONGITUDINALLYEXTENDING PORTION OF SAID MANDREL ADJACENT SAID HEATED PORTION TO COOLAND SET SAID THERMOPLASTIC ADHESIVE TO THEREBY MAINTAIN SAID STRIPS IN ABONDED RELATIONSHIP.